A new shape changing bone implant and instrument for the fixation of structures to include bone tissue. This new implant stores elastic mechanical energy to exert force on fixated structures to enhance their security and in bone affect its healing response. This unique implant locks into bone and then simultaneously expands and shortens to lock into bone and then pull the bone segments together. This implant once placed changes shape in response to geometric changes in the implant's and bone's materials structure. The implant may be fabricated from any biocompatible material that acts elastically when deformed including but not limited to nitinol, stainless steel, titanium, and their alloys as well as polymers such as polyetheretherketone, silicone elastomer and polyethylene. The implant is advanced over prior devices due to its: (1) method of operation, (2) high strength, (3) method of insertion, (4) compressive force temperature independence, (5) energy storing implant retention and delivery system, (6) compatibility with reusable or single use product configuration, (7) ability to act as a scaffold to conduct healing bone through the implant, (8) efficient and cost effective manufacturing methods, and (9) reduction in the steps required to place the device.L'invention concerne une nouvel implant osseux changeant de forme et un instrument pour la fixation de structures pour inclure le tissu osseux. Ce nouvel implant osseux stocke de l'énergie mécanique élastique pour exercer une force sur des structures fixées afin d'améliorer leur sécurité et pour avoir, dans l'os, un effet sur sa réponse de guérison. Cet implant unique se verrouille dans l'os et ensuite simultanément se dilate et se raccourcit pour se verrouiller dans l'os et ensuite rassembler les segments osseux. Cet implant, une fois placé, change de forme en réponse à des modifications géométriques dans la structure des matériaux de l'implant et de l'os. L'implant peut être fabriqué à partir de n'importe que
